This theme examines the repercussions of institutional complexity for global cooperation. Governance of global challenges increasingly involves a plethora of public, private and civil society actors across multiple scales and sectors. In this situation, global cooperation must develop across many institutional sites which are often only loosely interlinked. Comparative mapping of complex polycentric governance arrangements across policy fields is important to determine whether the flexibility, creativity, adaptability and responsiveness that such arrangements may entail can offset their challenges in terms of coordination, compliance and accountability.

Key questions include: how can we best conceptualize the institutional complexity which is here called ‘polycentrism’ (e.g. in terms of actor-networks, regime complexes, global assemblages, fragmented architectures, new constitutionalism, etc.)? How can we map institutional complexity around global cooperation, particularly in the governance of climate change, digital spaces, migration, and peacebuilding? Which practices of polycentric governance are particularly conducive to successful (or failed) global cooperation?  What can we learn from behavioral sciences for complex governance systems?